This invention relates to trigger actuated controls for portable electric tools wherein the rotational speed of the motor is controlled as a function of displacement of a trigger actuator. The trigger operator is connected to a movable actuator element of a variable resistor which is connected in circuit with a thyristor, the electric motor of the tool, and a source of electric power. A significant amount of heat is generated by electronic components of such speed control circuits, particularly by the thyristor which switches the electric power. Heat sinks are commonly provided in the control for dissipating the heat. As the electrical ratings of the tools increase, the power increases as does the quantity of heat to be dissipated. It is known to extend an internal heat sink externally of the control housing or to connect the thyristor to an external heat sink or to the case of the tool by a bolted connection or the like. Such practices require modification of the control and/or additional assembly steps to complete the mechanical connection, often performed by the tool manufacturer at the time of assembly of the control to the tool. Either solution generally represents increased cost to the tool manufacturer.